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NOTE Newtons laws does NOT seem to work here

  1. Feb 25, 2010 #1
    NOTE Newtons first law does NOT seem to work here, at the object does NOT keep moving at a constant speed, it actually stops.



    Am I missing somthing ???

    Wayne
     
    Last edited by a moderator: Sep 25, 2014
  2. jcsd
  3. Feb 25, 2010 #2

    russ_watters

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    Staff: Mentor

    It doesn't stop.
     
  4. Feb 25, 2010 #3
    It don't seem to stop when I watch it.
    EDIT: Darn, beaten.
     
    Last edited by a moderator: Sep 25, 2014
  5. Feb 25, 2010 #4

    Doc Al

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    What exactly are you talking about?
     
  6. Feb 25, 2010 #5
    Yes you are missing gravity. If I'm sitting on the space station and push some object towards earth, it will come back up again later on. If the space station has a circular orbit, the thrown object will have an elliptic orbit. Sometimes closer to earth, sometimes farther away. So it will move up and down relatively to me.

    Torquil
     
    Last edited by a moderator: Sep 25, 2014
  7. Feb 25, 2010 #6
    Looking at it again, I suppose there is not enough evidence in the video. But it looks like to me that its either slowing down or stopped and just rotating, or even going if anything in another direction.

    Wayne
     
  8. Feb 25, 2010 #7
    K thx.

    Ok, if the Moon can move the tides, and they must weigh Billions of tones, why does it not move far lighter things on this Earth and things like space walkers ???

    Wayne
     
  9. Feb 25, 2010 #8
    The moon does influence the movement of space walkers.

    Also, its gravitational field acts on every object on earth the same. The difference between its influence on land and water is that land is rigid and water is not. The water is able to flow, and therefore the effect of the lunar influence is different.

    EDIT: I'm not saying that the strength of the gravity from the moon is the same all over the earth, of course. See post #9 for the explanation of the tides.

    Remember, the gravitational force between two objects is proportional to the product of the two masses, so the force acting on the billion of tonnes of water is proportionally larger.

    Torquil
     
  10. Feb 25, 2010 #9

    Matterwave

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    The moon affects the tides by an uneven pull between the areas of the Earth closer to the moon and the areas of the Earth farther from the moon. An astronaut, being small, does not feel this difference in pull appreciably; he feels more or less the same force throughout his entire body.
     
  11. Feb 25, 2010 #10
    Ahh,the gravitational force between two objects is proportional to the product of the two masses.

    Great get it.

    Wayne
     
  12. Feb 25, 2010 #11
    K thx.

    And thx to all.

    Wayne
     
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